Fire safety systems are a ubiquitous feature of modern building infrastructure and are critical for safeguarding the occupants of buildings and other protected areas against various hazardous conditions. Fire safety systems typically include a plurality of smoke detectors that are distributed throughout a building or area, each connected to one or more centralized alarm panels that are configured to activate notification devices (e.g., strobes, sirens, etc.) to warn occupants of the building or area if a hazardous condition is detected.
A conventional smoke detector includes a housing that defines a detection chamber that is partially open to a surrounding environment. The detection chamber may contain a light source and a photoelectric sensor that may be separated by a septum that prevents light emitted by the light source from traveling directly to the photoelectric sensor. However, if smoke from the surrounding environment enters the detection chamber, particulate in the smoke may provide a reflective medium by which light from the light source may be reflected to the photoelectric sensor. If the particulate in the detection chamber is sufficiently dense and reflects enough light to the photoelectric sensor, the output of the photoelectric sensor may exceed a predefined “alarm threshold” and may cause an associated alarm panel to initiate an alarm.
A shortcoming that is associated with conventional smoke detectors is that the components of such detectors can become dirty over time due to the buildup of dirt, dust, and other particulate which may adversely affect the operation of a smoke detector. For example, such “non-smoke” particulate may accumulate in the detection chamber of a smoke detector and may provide a reflective medium similar to smoke. This may cause a photoelectric sensor of a smoke detector to generate output indicative of an alarm condition (e.g., a fire) when no such condition exists. Additionally, even if the amount of non-smoke particulate that has accumulated in a smoke detector is not by itself sufficient to result in an alarm, a combination of the non-smoke particulate and an amount of “smoke,” that would not by itself produce an alarm, may cause a photoelectric sensor to generate output above an associated alarm threshold. The non-smoke particulate may therefore reduce the operating range of a smoke detector by artificially pushing the sensor output nearer the alarm threshold. This may be of particular concern with regard to smoke detectors that are located in areas that are normally dirty with highly variable levels of airborne particulate (e.g., loading docks, boiler rooms, etc.).
In view of the foregoing, it is important to clean smoke detectors in a fire safety system periodically to ensure that the operating ranges of the smoke detectors are not significantly compromised by the accumulation of non-smoke particulate. However, the task of cleaning smoke detectors can be tedious and time consuming, especially in fire safety systems that include dozens, hundreds, or even thousands of smoke detectors. The sheer scope of the population of detectors to be cleaned combined with the relatively “unknown” dirty state can result in mismanaged cleaning activities. The burden of this task can be reduced by identifying which smoke detectors in a fire safety system are actually dirty and in need of cleaning and further, knowing how effective the cleaning process was. However, operational data that facilitates the identification of dirty smoke detectors is typically stored in the alarm panels of a fire safety system, which themselves are often numerous, widely distributed, and difficult to access.
In view of the forgoing, it would be advantageous to provide a system and a method for providing a convenient indication of which smoke detectors in a fire safety system are dirty and to what degree they are dirty. It would further be advantageous to provide such a system and method that can predict when the smoke detectors in a fire safety system will require cleaning. It would further be advantageous to provide such a system and method that can provide a convenient indication of the stability of the environment the smoke detector is installed in and, finally, how well the smoke detectors in a fire safety system have been cleaned.